Help! Mid cycle bleeding...

I am CD 16 today and I woke up to blood in my underwear like my period. When I was on my period this last time (two weeks ago) it was awful. Extremely heavy flow, clotty, and crampy. I had a sneaking suspicion it may have been another chemical but I wasn't able to test in time. It also lasted 9 days heavy almost the entire time. My usual cycle is ~7 days with the last 1-2 being spotting.

I have been having a pain on my right side flank off and on since Friday. It almost feels like a gas bubble, but it's in an odd place. Then last night I started having lower left side back pain like I did when I miscarried, though not quite as severe.

My question is, has anyone experienced something similar and know what happened? I have put a call in to my doctor's office, waiting to hear back now. I hope they don't tell me to go to the hospital. 😩